An important result from the analysis of measured radiation spectra is an estimation of identified nuclide activities. These activity estimations are based on analyzing the system response using a designated efficiency calibration. The accuracy of the activity estimation depends directly on the accuracy of the efficiency calibration. When the measurement is conducted with limited knowledge of the source geometry the efficiency calibration is often based on an average expected geometry. When the actual source geometry differs from the average expected efficiency calibration by having a significant amount of unaccounted-for attenuating shielding, the reported activity will be significantly underestimated. However, there are spectral characteristics that can be used to both flag for the presence and then correct for significant shielding that would otherwise skew nuclide activity estimations.
Accordingly, it is a principal object of the invention to provide a system to reliably determine when significant source shielding is present to provide both a flag to alert an operator and possibly to trigger further automatic activity correction analysis.
It is a further object of the invention to provide such a system that uses spectral characteristics to correct for significant shielding that would otherwise skew nuclide activity estimations.
Other objects of the invention, as well as particular features and advantages thereof, will be apparent or be elucidated in the following description and the accompanying drawing figures.